1. Field of the Invention
This invention relates generally to a shaft mounting mechanism and more particularly to a shaft mounting mechanism for attachment of a data transmission device to a tapered, rotating and instrumented shaft.
2. Description of the Related Art
Data transmission between rotating and stationary transmission points is conventionally achieved by attaching an electromechanical slip ring to a rotating member such as a shaft. The slip ring has channels contacting respective brushes fixed to a stationary component, thereby providing a continuous electrical connection between rotating and stationary components. Slip rings are used in a wide range of applications from radar antennae to nearly every type of electric rotating machinery.
These brushes often wear out from the friction encountered during use, causing a failure of the contact. Also, the period preceding complete failure is marked by intermittent losses of contact. In addition, specific strain gage applications require a low background noise environment which does not exceed a few microvolts.
Data transmission devices, such as the Model 1200B Series Universal Data Coupler System, which is commercially available from the Wireless Data Corporation of Mountain View, Calif., operate without the need for direct contact of the transmission device with the instrumented surface of the shaft. However, attachment of such devices to tapered, rotating shafts of helicopter tail rotors for the purpose of measuring strain gage output has been difficult since there are no adequate internal or external means for securing the apparatus to prevent radial or axial slippage when attached to a tapered shaft. In addition, any attachment method must minimize the introduction of loads which might affect the accuracy of strain gage readings from the instrumented surface of the shaft.